FRP Confinement of Tuff and Clay Brick Columns: Experimental Study and Assessment of Analytical Models

Abstract

In recent years, fiber-reinforced polymer (FRP) wrapping effectiveness has been clearly confirmed especially with reference to concrete structures. Despite evident advantages of FRP based confinement on members subjected to compressive overloads due to static or seismic actions, the use of such technique in the field of masonry has not been fully explored. Thus, to assess the potential of confinement of masonry columns, the present paper shows the results of an experimental program dealing with 18 square cross sections (listed faced tuff or clay brick) masonry scaled columns subjected to uniaxial compression load. In particular, three different confinement solutions have been experimentally analyzed in order to evaluate and compare the effectiveness of uniaxial glass FRP, carbon FRP, and basalt FRP laminates wrapping. The main experimental outcomes are presented and discussed in the paper considering mechanical behavior of specimens, axial stress-axial strain relationships, and effective strains at failure on the reinforcement. Test results have showed that the investigated confining systems are able to provide significant gains both in terms of compressive strength and ductility of masonry columns. Results of the presented experimental activity along with data available in the literature have been finally used to assess the reliability of the main existing analytical models; refined equations have been then proposed to minimize the scattering between theoretical predictions and experimental available data.